Power-transmission device.



PATENTED AUG. 30, 1904.

P. N.'NELSON.

POWER TRANSMISSION DEVICE.

APPLIGATION FILED MAY 10, 1904.

N0 MODEL.

UNITED STATES Patented August 30, 1904.

PETER N. NELSON, OF GALESVILLE, WISCONSIN.

POWER-TRANSMISSION DEVICE.

SPECIFICATION forming part of Letters Patent No. 768,883, dated August30, 1904. Application filed May 10,1904- Serial No. 207,270. (No model.)

To (all whom it may concern.-

Be it known that I, PETER N. NELSON, a citi- Zen of the United States,residing at Galesville, in the county of Trempealeau and State .ofWVisconsin, have invented certain new and useful Improvements inPower-Transmission Devices; and I do declare the following to be a full,clear, and exact description of the invention, such as ,will enableothers skilled inthe art to which it appertains to make and use thesame, reference being had to the accompanying drawings, and to thefigures of reference marked thereon, which form a part of thisspecification.

My invention relates to driving-gear particularly adapted to be used onmotor-vehicles, and is a device for the transmission of power through acompensating spring, which, however, can be applied to any power-drivenmachine; and my invention has for its object to transmit power to themoving parts of a machine through the agency of a compensating spring inorder to avoid all shock or jerk from the sudden application of power tosaid moving parts.

With this object in view my invention consists in the novel constructionof the several parts of my device, as will be first fully described andafterward specifically pointed out in the appended claims.

Referring to the accompanying drawings, Figure 1 is a vertical sectionalview taken on line 1 1 of Fig. 2. Fig. 2 is a vertical transversesectional view taken on line 2 2 of Fig. 1, and Fig. 3 is a fragmentaryview of the bottom portion as shown in Fig. 1.

Like numerals of reference indicate the same parts throughout theseveral figures, in which- 1 indicates the shaft which is to be driven,and 2 indicates the collet, which is secured permanently to said shaft 1by a key or by any suitable fastening means. By referring to Fig. 2 itwill be seen that the said collet 2 is in the form of a disk having therear plate 3 and the annular flange 1, which are formed by hollowing outor recessing the said collet, as shown in Fig. 2. sets within saidcollet and which carries a sprocket 6, rigidly connected to said disk 5.

5 indicates a disk which The said disk is provided, as shown in Fig. 1,

with a rim or flange 7, extending within the collet2 and close to theannular flange thereof. The said rim or flange 7 is substantiallysemicircular in side elevation and, as clearly shown in Fig. l, is notannular for purposes which will be hereinafter fully described.

8 indicates a heavy coil-spring, the end 9 thereof being particularlyheavy and provided with a projection 10, which enters the groove 11 inthe rim or flange 7 of the disk 5, the extreme end of said spring beingflattened, as shown at 12. The inner end 13 of said spring is alsoenlarged and is provided with-what might be termed a spur 14, theextreme end of said spring being backwardly beveled, as shown at 15. Thecollet 2 is cut away or provided with a groove 16 to receive the end 13of the spring 8, as clearly shown inFig. 1.

17 indicates a stop, which is preferably dovetailed in the flange 4 ofthe collet 2.

Having thus described the several parts of my invention, its operationis as-follows, supposing that power was applied by means of a suitablesprocket-chain to the sprocket 6, so as to revolve said sprocket in thedirection of the arrow. (Shown in Fig. 1.) The normal tendency of thespring 8 holds the end 18 of the rim or flange 7 in contact with thestop 17, as shown in Fig. 1, when no power is being applied-to thesprocket 6. Consequently when power is applied to the sprocket 6, saidsprocket 6 being securely attached to the disk 5, carrying the rim orflange 7, the collet tends to revolve with the said sprocket 6. Thespring 8, however, being connected to said rim or flange 7, asdescribed, the tendency of said rim or flange to revolve is resisted bythe tendency of the spring 8 to revolve said rim or flange 7 in theopposite direction. As soon as the power transmitted to the rim orflange 7 overcomes the pressure of the spring 8 said rim or flange 7,together with the sprocket 6 and disk 5, start to revolve, which means awinding of the spring 8. As soon, however, as

the spring 8 commences to wind the end 13 of said spring tends to followthe movement of the end 9 of said spring, and therefore eX- erts atendency to revolve the collet 2, to which the end 13 of the spring issecured. It

is therefore seen that should power be suddenly applied to the sprocket6 the rim or flange 7 would be given a sudden impulse, which impulsewould shock or jerk the shaft 1 were said rim or flange 7 or sprocket 6di rectly connected to said shaft 1; but in my construction the suddenimpulse given the rim or flange 7 acts directly on the end 9 of thespring 8, and instead of giving a shock or jerk to the shaft 1 thesudden application of power merely tends in the first place to wind thespring 8. However, as the inner end 13 of said spring 8 tends to followthe movement of the end 9 a gradually-increasing and resilient impulseis given the collet 2, which is connected to the shaft 1, so that saidcollet and shaft start to revolve gradually instead of suddenly, aswould be the case were the sprocket 6 directly connected to the shaft 1,thereby obviating any shock or jerk arising from the sudden applicationof power.

While I am aware that compensating springs have been used similarlybefore, I wish to lay particular stress upon the following construction:The stop 17 arranged as shown in Fig. 1, and the form of the outer end 9of the spring 8, which operates as follows: Should the power required toturn the shaft 1 be greater than the extension strain of the spring 8,it is obvious that ordinarily the said spring 8 would wind as far aspossible and then break upon the application of additional power. In myconstruction, however, should the power required to turn the shaft 1 begreater than the extension strain of the spring 8 said spring will bewound until the face 12 of the end 9 is in contact with the stop 17. Thepower thus transmitted through the stop 17 amounts to the differencebetween the entire power and that transmitted through the spring. On theother hand, should the sprocket be thrown in the direction of the arrowin Fig. 1, which would wind the spring 8 either partially or until theend thereof was in contact with the stop 17 and should the power hesuddenly reversed the rim or flange 7 of the disk 5 would be revolved inthe contrary direction until the end 18 of said rim or flange 7 came incontact with the stop 17, as shown in Fig. 1. IV hen as soon as the saidend 18 of the rim or flange 7 comes in contact with the stop 17, theconnection between the sprocket 6 and the shaft 1 is direct and powertending to revolve the sprocket 6 is directly ap plied to the shaft 1 byreason of the stop 17. A feature of my invention which is ofconsiderable importance is the fact that an accidental break of thecompensating spring will have no effect upon the transmission of powerto the shaft 1, for, as is shown in Fig. 3, the end of the rim or flange7, which engages the end. 9 of the spring 8, is shown in contact withthe stop 1.7. Supposing, therefore, that by reason of a flaw orotherwise the spring 8 was accidentally broken, the application of powerto the sprocket 6 would revolve the rim or flange 7 until the endthereof came in contact with the stop 17, which would transmit themotion of said rim or flange to the stop 17, and therefore turn theshaft 1. It is of course obvious that the compensating feature of thedevice would in this instance be destroyed, and the sudden applicationof power would shock the mechanism the same as though the sprocket 6were directly secured to the shaft 1; but it must be remembered that themachine would not be disabled on account of an accidental breaking ofthe spring, and the same could be run as well as though the sprocketwere directly secured on the shaft 1 until opportunity presented itselfto installa new compensating spring.

Having thus described the several parts of my invention and set forththe operation and advantages thereof, it is obvious that thispower-transmission device can be applied. to many and varied machines,such as automobiles, and it is also obvious that my device can be usedin mills or wherever power is transmitted by belting and shafting, itbeing of course understood that the substitution of a belt orbevel-gearing for a sprocket-chain would immediately suggest itselfwherever the application of a belt or bevel -gearing would bepreferable. I furthermore do not wish to be understood as limitingmyself to the exact construction as herein set forth, as various slightchanges may be made therein which would fall within the limit and scopeof my invention, and I consider myself clearly entitled to all suchchanges and modifications.

What I claim as my invention, and desire to secure by Letters Patent ofthe United States, is

1. In a power-transmission device, the combination with a shaft ofacollet secured thereon, said collet being hollowed out and providedwith an annular flange thereon, a disk associated with said collet, asubstantially semicircular rim or flange thereon, a sprocket secured tosaid disk, acoil-spring located within said hollow collet having itsouter end enlarged and in engagement with said rim or flange on saiddisk, the inner end of said spring being enlarged and connected to saidcollet, and a stop secured to the annular flange of said collet adaptedto be engaged by the said enlarged outer end of said spring, and also bythe said rim or flange of said disk, substantially as described and forthe purposes set forth.

2. In a power-transmission device, the combination with a shaft, of acollet secured there on, a disk associated with said collet, asprocket-wheel carried on said. disk, a substantially semicircular rimor flange on said disk and a coil-spring having an outer enlarged end inengagement with said rim or flange and an inner enlarged end connectedto IIO said collet and a stop on said collet adapted to be engaged bythe said outer enlarged end of said spring and also by the said rimorflange on said disk, substantially as described.

3. In a power transmission device, the combination with a shaft of acollet secured thereon, a sprocket associated with said collet, a-rim orflange associated with said sprocket and adapted to be moved thereby, acoil-spring having its outer end in engagement with said rim or flange,and its inner end in engagement with said collet, and a stop onsaidcollet adapted to limit the movement of said rim or flange in bothdirections, substantially as described.

4. In a power-transmission device, the combination with a shaft of acollet secured there on, a sprocket-wheel associated with said collet, arim or flange associated with said sprocket and adapted to be movedthereby, a coil-spring having an enlarged outer end in engagement withsaid rim or flange and its inner end connected to said collet and a stopsecured to said collet adapted to limit the movement of said rim orflange in both directions, substantially as described.

5. In a power-transmission device, the combination of a collet and asprocket associated therewith, a rim or flange associated with saidsprocket and adapted to be moved thereby, a coil-spring having anenlarged outer end and provided with a projection adapted to engage saidrim or flange, the inner end of said spring being enlarged and providedwith a spur and adapted to engage said collet, a stop secured tosaidcollet to receive the said enlarged outer end of said spring tolimit the movement of said rim or flange in one direction and adapted toreceive the said rim or flange to limit the movement thereof in thereverse direction, substantially as described.

In testimony whereof I aflix my signature in presence of two witnesses.

PETER N. NELSON.

